The present invention relates generally to a multilayered volume hologram structure comprising a transparent image bearing hologram, which is pasted on a surface of a photograph or personal information area attached to ID cards, exam cards, passports, etc. for the purpose of ensuring security and a label for making such a multilayered volume hologram structure, and more particularly to a multilayered volume hologram structure which cannot possibly be fraudulently altered or otherwise falsified, and a label for making such a multilayered volume hologram structure.
In recent years, means for preventing fraudulent alternation or falsification of identity cards, etc. have been strongly demanded, for instance, so as to certainly identify who carries an ID card as who is characterized by identifying data born thereon. Such falsification preventive techniques, for instance, are disclosed in JM-B 5-48215 and JP-A 5-201181 wherein an image bearing hologram is used. The image of the image bearing hologram has the same function as an engraving or the like on a conventional ID card or the like.
Especially according to the means disclosed in the latter publication, when the protective film is stripped off for the purpose of falsification or the like, the hologram layer fractures due to its softness to make it impossible to reconstruct the hologram image, thereby preventing falsification as by making a photograph replacement. When a rigid plastic film is used as the surface protective film, however, the hologram layer is often perfectly stripped off following the surface protective film. In this case, there is no sign of a photograph replacement or falsification of information. It is thus strongly demanded to improve this prior art means in such a way that the function of preventing falsification is much more improved for the purpose of ensuring security.
According to a first aspect of the invention, there is provided a multilayered volume hologram structure comprising a substrate for a certificate or the like, and a first adhesive layer, a volume hologram layer and a surface protective film laminated on said substrate in the described order, characterized in that a peel strength, with which a multilayer structure consisting of said volume hologram layer and said surface protective film is peeled from said substrate, is greater than a breaking strength or a tensile strength at 1% elongation of said multilayer structure consisting of said volume hologram layer and said surface protective film.
The multilayered volume hologram structure according to the first aspect of the invention is further characterized in that the peel strength, with which said multilayer structure consisting of said volume hologram layer and said surface protective film is peeled from said substrate (e.g., a photograph), is 0.1 Kg/25 mm to 5.0 Kg/25 mm, and a multilayer structure comprising said first adhesive layer, said volume hologram layer and said surface protective film laminated on said substrate in the described order has a breaking strength or a tensile strength at 1% elongation of 0.01 Kg/mm2 to 5.0 Kg/mm2.
The multilayered volume hologram structure according to the first aspect of the invention is further characterized in that another adhesive layer is interleaved between said volume hologram layer and said surface protective film.
The multilayered volume hologram structure according to the first aspect of the invention is further characterized in that said surface protective film is subjected to a hard coat treatment on a surface thereof.
The multilayered volume hologram structure according to the first aspect of the invention is further characterized in that said surface protective film is subjected to a release treatment on a surface thereof.
The present invention also provides a label for making the multilayered volume hologram structure according to the first aspect of the invention, characterized by comprising a release paper and a first adhesive layer, a volume hologram layer and a surface protective film laminated on said release paper in the described order, said label being pasted on a substrate for a certificate or the like upon removal of said release paper.
The label for making the multilayered volume hologram structure according to the first aspect of the invention is further characterized in that a peel strength, with which a multilayer structure consisting of said volume hologram layer and said surface protective film is peeled from said substrate, is 0.1 Kg/25 mm to 5.0 Kg/25 mm, and a multilayer structure comprising said first adhesive layer, said volume hologram layer and said surface protective film laminated in the described order has a breaking strength or a tensile strength at 1% elongation of 0.01 Kg/mm2 to 5.0 Kg/mm2.
The label for making the multilayered volume hologram structure according to the first aspect of the invention is further characterized in that said volume hologram layer and said surface protective film are laminated together with said first adhesive layer interleaved therebetween.
The volume hologram structure according to the first aspect of the invention ensures prevention of falsification because, immediately upon making a photograph replacement or falsification of the information area, the volume hologram image breaks down certainly. With the label for making the multilayered volume hologram structure according to the first aspect of the invention, it is easy to make the multilayered volume hologram structure according to the first aspect of the invention.
According to a second aspect of the invention, there is provided a multilayered volume hologram structure comprising a substrate, and a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said substrate in the described order, characterized in that said second adhesive layer is weaker in adhesion than said first adhesive layer, and when said surface protective film is released from said multilayered volume hologram structure in a given releasing direction, a releasing line is produced in a direction at right angles with respect to said releasing direction.
According to the second aspect of the invention, there is also provided a multilayered volume hologram structure comprising a substrate, and a third adhesive layer, a colored sheet, a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said substrate in the described order, characterized in that said second adhesive layer is weaker in adhesion than said first adhesive layer and said third adhesive layer, and when said surface protective film is released from said multilayered volume hologram structure in a given releasing direction, a releasing line is produced in a direction at right angles with respect to said release direction.
The second multilayered volume hologram structure of the invention is also characterized in that a peel strength, with which said surface protective film is released from said multilayered volume hologram structure, is 0.001 Kg/25 mm to 0.1 Kg/25 mm, and a peel strength between said substrate and said volume hologram layer is 0.1 Kg/25 mm to 5.0 Kg/25 mm.
The second multilayered volume hologram structure of the invention is further characterized in that said volume hologram layer is made up of a photosensitive material used for recording a dry type of volume phase hologram, which comprises a matrix polymer, a photopolymerizable compound, a photopolymerization initiator and a sensitizing dye.
One label for making the second multilayered volume hologram structure of the invention is a multilayered volume hologram structure comprising a release paper, and a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said release paper in the described order, characterized in that said second adhesive layer is weaker in adhesion than said first adhesive layer, and when said surface protective film is released from said multilayered volume hologram structure in a given releasing direction, a releasing line is produced in a direction at right angles with respect to said releasing direction.
Another label for making the second multilayered volume hologram structure of the invention is a multilayered volume hologram structure comprising a release paper, and a third adhesive layer, a colored sheet, a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said substrate in the described order, characterized in that said second adhesive layer is weaker in adhesion than said first adhesive layer and said third adhesive layer, and when said surface protective film is released from said multilayered volume hologram structure in a given releasing diretion, a releasing line is produced in a direction at right angles with respect to said releasing direction.
When the surface protective film is released from the second multilayered volume hologram structure of the invention, releasing layers are produced. When the recorded hologram is copied, the copy can be distinguished from the original hologram because the releasing layers are copied at the same time. Even when a hologram with the releasing lines formed thereon is pasted on another substrate for forging purposes, the hologram can be distinguished from the original hologram because of the presence of the releasing lines. Thus, prevention of falsification can be ensured. With the label for making the second multilayered volume hologram structure of the invention, the second multilayered volume hologram structure of the invention can be easily prepared.
According to a third aspect of the invention, there is provided one multilayered volume hologram structure comprising a substrate for a certificate or the like, and a heat sealing layer, a volume hologram layer, an adhesive layer and a surface protective film laminated on said substrate, characterized in that the whole surface of said multilayered volume hologram structure is heat-sealed.
According to the third aspect of the invention, there is provided another multilayered volume hologram structure comprising a certificate for a certificate or the like, and an adhesive layer, a volume hologram layer, a heat sealing layer and a surface protective layer laminated on said substrate, characterized in that said volume hologram layer and an end portion thereof are coated with said surface protective film, said volume hologram layer is laminated on said substrate, and only the overall peripheral end of said multilayered volume hologram structure including the overall peripheral end of said volume hologram layer is heat-sealed.
The third multilayered volume hologram structure of the invention is characterized in that heat sealing has been done at 100xc2x0 C. to 180xc2x0 C.
One label for making the third multilayered volume hologram structure of the invention is characterized by comprising a release paper, and a heat sealing layer, a volume hologram layer, an adhesive layer and a surface protective layer laminated on said release paper in the described order.
Another label for making the third multilayered volume hologram structure of the invention is characterized by comprising a release paper, and an adhesive layer, a volume hologram layer, a heat sealing layer and a surface protective film laminated on said release paper in the described order,
a size of said surface protective film being such that, upon said label laminated on a substrate for a certificate or the like, said surface protective film covers said volume hologram layer including a whole periphery of an end thereof.
When the third multilayered volume hologram structure of the invention is forcibly delaminated, the volume hologram display layer breaks down certainly, thereby ensuring prevention of falsification as by making a photograph replacement. With the label for making the third multilayered volume hologram layer of the invention, the third multilayered volume hologram structure can be easily prepared.
A fourth multilayered volume hologram structure of the invention is characterized by comprising a substrate and a hologram layer pasted on said substrate, said hologram layer being provided with a surface protective film on a surface thereof, and further including a second adhesive layer for bonding together said surface protective film and said hologram layer and a first adhesive layer for bonding together said hologram layer and said substrate, either one of said adhesive layers having an adhesion force profile in its own plane.
A label for making the fourth multilayered volume hologram structure of the invention is a label used for making the fourth multilayered volume hologram structure of the invention characterized by comprising a release paper, and a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said release paper in the described order, said label being pasted on a substrate for a certificate or the like upon removal of said release paper therefrom, and either one of said first adhesive layer and said second adhesive layer having an adhesive force profile in its own plane.
When the fourth multilayered volume hologram structure of the invention is forcibly delaminated, the volume hologram display layer breaks down certainly, thereby ensuring prevention of falsification as by making a photograph replacement. With the label for making the fourth multilayered volume hologram layer of the invention, the fourth multilayered volume hologram structure can be easily prepared.
One embodiment of a fifth multilayered volume hologram structure of the invention comprises a substrate, and a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said substrate in the described order, and is characterized in that microcapsules, each encapsulated with a material capable of breaking said hologram layer, are incorporated in said adhesive layers, so that said microcapsules can break down upon delamination of said multilayered volume hologram structure.
Another embodiment of the fifth multilayered volume hologram structure of the invention comprises a substrate, and a third adhesive layer, a coloring sheet, a first adhesive layer, a volume hologram, a second adhesive layer and a surface protective film laminated on said substrate in the described order, and is characterized in that microcapsules, each encapsulated with a material capable of breaking said volume hologram layer, are incorporated in said first and second adhesive layers disposed adjacent to said hologram layer, so that said microcapsules can break down upon delamination of said multilayered volume hologram structure.
The fifth multilayered volume hologram structure of the invention is also characterized in that a material forming said volume hologram layer comprises a matrix polymer, a photopolymerizable compound, a photopolymerization initiator and a sensitizing dye, and said material capable of breaking said volume hologram layer comprises an organic solvent having a solubilizing action on said volume hologram layer forming material and/or a plasticizer having a swelling action on said volume hologram layer forming material.
One embodiment of a label for making the fifth multilayered volume hologram structure of the invention is a label used for making the first embodiment of the aforesaid fifth multilayered volume hologram structure. This label comprises a release paper, and a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said release paper in the described order, and is characterized in that microcapsules, each encapsulated with a material capable of breaking said volume hologram layer, are incorporated in said adhesive layers, so that said microcapsules can break down upon delamination of said multilayered volume hologram structure.
Another embodiment of the label for making the fifth multilayered volume hologram structure of the invention is a label for making the second embodiment of the fifth multilayered volume hologram structure. This label comprises a release paper, and a third adhesive layer, a coloring sheet, a first adhesive layer, a volume hologram, a second adhesive layer and a surface protective film laminated on said release paper in the described order, and is characterized in that microcapsules, each encapsulated with a material capable of breaking said volume hologram layer, are incorporated in said adhesive layers disposed adjacent to said volume hologram layer, so that said microcapsules can break down upon delamination of said multilayered volume hologram structure.
The label for making the aforesaid fifth multilayered volume hologram structure is characterized in that a material forming said volume hologram layer comprises a matrix polymer, a photopolymerizable compound, a photopolymerization initiator and a sensitizing dye, and said material capable of breaking said volume hologram layer comprises an organic solvent having a solubilizing action on said volume hologram layer forming material and/or a plasticizer having a swelling action on said volume hologram layer forming material.
When, upon a release from the adhesive layers, the fifth multilayered volume hologram structure of the invention is re-laminated thereon, the volume hologram layer breaks down on contact with the volume hologram layer breaking material coming out of the microcapsules upon a breakdown. As a result, even when the photograph pasted on the multilayered volume hologram structure is replaced by another photograph, such a photograph replacement can be detected by identifying the presence of the broken hologram. It is thus possible to make sure of prevention of falsification. With the label for making the fifth multilayered volume hologram structure, the fifth multilayered volume hologram structure can be easily prepared.
One embodiment of a sixth multilayered volume hologram structure of the invention is characterized by comprising a substrate for a certificate or the like, and an adhesive layer, a volume hologram layer containing fine particles having an average primary particle size of 1 nm to 100 nm and used in an amount of 10 parts by weight to 100 parts by weight per 100 parts by weight of a photosensitive material, and a surface protective film laminated on said substrate in the described order.
This structure is also characterized in that said fine particles are each a fluorescent fine particle emitting fluorescence upon irradiation with ultraviolet radiation.
Another embodiment of the sixth multilayered volume hologram structure of the invention is characterized by comprising a substrate for a certificate or the like, and an adhesive layer, a volume hologram layer containing plastic particles or glass beads having a refractive index substantially equal to that of a photosensitive material and used in an amount of 10 parts by weight to 100 parts by weight per 100 parts by weight of said photosensitive material, and a surface protective film laminated on said substrate in the described order.
The aforesaid sixth multilayered volume hologram structure is also characterized in that said volume hologram layer and said surface protective film are laminated together with an additional adhesive layer interleaved therebetween.
One embodiment of a label for making the sixth multilayered volume hologram structure is characterized by comprising a release paper, and an adhesive layer, a volume hologram layer containing fine particles having an average primary particle size of 1 nm to 100 nm and used in an amount of 10 parts by weight to 100 parts by weight per 100 parts by weight of a photosensitive material, and a surface protective film laminated on said release paper in the described order.
This label is also characterized in that said fine particles are each a fluorescent fine particles emitting fluorescence upon irradiation with ultraviolet radiation.
Another embodiment of the label for making the sixth multilayered volume hologram structure of the invention is characterized by comprising a release paper, and an adhesive layer, a volume hologram layer containing plastic particles or glass beads having a refractive index substantially equal to that of a photosensitive material and used in an amount of 10 parts by weight to 100 parts by weight per 100 parts by weight of said photosensitive material, and a surface protective film laminated on said substrate in the described order.
This label is also characterized in that said volume hologram layer and said surface protective film are laminated together with an additional adhesive layer interleaved therebetween.
When the sixth multilayered volume hologram structure of the invention is forcibly delaminated, the volume hologram layer breaks sown. It is thus possible to make sure of prevention of falsification as by making a photograph replacement. With the label for making the sixth multilayered volume hologram structure, the sixth multilayered volume hologram structure can be easily prepared.
One embodiment of a seventh multilayered volume hologram structure of the invention is characterized by comprising a substrate for a certificate or the like, and an adhesive layer, a volume hologram layer, a resin layer containing a monomer or a plasticizer and a surface protective film laminated on said substrate in the described order.
This multilayered volume hologram structure is also characterized in that said resin layer containing a monomer or a plasticizer and said surface protective film are laminated together with an additional adhesive layer interleaved therebetween.
Another embodiment of the seventh multilayered volume hologram structure of the invention is characterized by comprising a substrate for a certificate or the like, and an adhesive layer, a volume hologram layer, a brittle layer, an adhesive layer and a surface protective film laminated on said substrate in the described order.
One embodiment of a label for making the seventh multilayered volume hologram structure of the invention is characterized by comprising a release paper, and an adhesive layer, a volume hologram layer, a resin layer containing a monomer or a plasticizer and a surface protective film laminated on said release paper in the described order.
This multilayered volume hologram structure is also characterized in that said monomer or plasticizer-containing resin layer and said surface protective film are laminated together with an additional adhesive layer interleaved therebetween.
Another embodiment of the label for making the seventh multilayered volume hologram structure of the invention is characterized by comprising a release paper, and an adhesive layer, a volume hologram layer, a brittle layer, an adhesive layer and a surface protective film laminated on said release paper in the described order.
When the seventh multilayered volume hologram structure of the invention is forcibly delaminated, the volume hologram layer remains on the substrate such as a photograph. It is thus possible to make use of the brittleness of the hologram layer to ensure prevention of falsification as by making a photograph replacement. With the label for making the seventh multilayered volume hologram structure, the seventh multilayered volume hologram structure can be easily prepared.
One embodiment of an eighth multilayered volume hologram structure of the invention is characterized by comprising a substrate for a certificate or the like, and a first adhesive layer, a volume hologram layer and a surface protective film laminated on said substrate in the described order, and further including between said volume hologram layer and said surface protective film a patterned area for varying relative adhesion between said volume hologram layer and said surface protective film in a site-dependent manner, so that upon an intentional release of a multilayer structure from said substrate, said volume hologram layer is broken or elongated while said volume hologram layer is separated into a portion adhering to said substrate and a portion adhering to said surface protective film.
This multilayered volume hologram structure is also characterized in that upon irradiation with ultraviolet radiation or heating, one of said volume hologram layer or said surface protective film shows adhesion to the other or the relative adhesion between said volume hologram layer and said surface protective film decreases.
Another embodiment of the eighth multilayered volume hologram structure of the invention is characterized by comprising a substrate for a certificate or the like, and a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said substrate in the described order, and further including between said second adhesive layer and said surface protective film a patterned area for varying mutual adhesion between said second adhesive layer and said surface protective film in a site-dependent manner, so that upon an intentional release of an multilayer structure from said substrate, said volume hologram layer is broken or elongated while said volume hologram layer is separated into a portion adhering to said substrate and a portion adhering to said surface protective film.
This multilayered volume hologram structure is also characterized in that said patterned area for varying said adhesion in a site-dependent manner is a pattern of release agent layer.
Further, this multilayered volume hologram structure is characterized in that said patterned area for varying said adhesion in a site-dependent manner is an adhesion-enhancing pattern of primer layer.
Furthermore, this multilayered volume hologram structure is characterized in that said patterned area for varying said adhesion in a site-dependent manner is obtained by treating a surface of said surface protective film to be laminated in such a way that said surface is easily bondable.
Yet another embodiment of the eighth multilayered volume hologram structure of the invention is characterized by comprising a substrate for a certificate or the like, and a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said substrate in the described order, and further including between said first adhesive layer and said volume hologram layer a patterned area for varying relative adhesion between said first adhesive layer and said volume hologram layer in a site-dependent manner, so that upon an intentional release of a multilayer structure from said substrate, said volume hologram layer is broken or elongated while said volume hologram layer is separated into a portion adhering to said substrate and a portion adhering to said surface protective film.
One embodiment of a label for making the eighth multilayered volume hologram structure of the invention is a label used for making the aforesaid eighth multilayered volume hologram structure. The aforesaid label is characterized by comprising a release paper, and a first adhesive layer, a volume hologram layer and a surface protective film laminated on said substrate in the described order, and further including between said volume hologram layer and said surface protective film a patterned area for varying relative adhesion between said volume hologram layer and said surface protective film in a site-dependent manner. This label is pasted on a substrate for a certificate or the like upon a release of said release paper therefrom.
Another embodiment of the label for the eighth multilayered volume hologram structure of the invention is a label used for making the second embodiment of the eighth multilayered volume hologram structure. The aforesaid label is characterized by comprising a release paper, and a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said substrate in the described order, and further including between said second adhesive layer and said surface protective film a patterned area for varying relative adhesion between said second adhesive layer and said surface protective film in a site-dependent manner. This label is pasted on a substrate for a certificate or the like upon a release of said release paper therefrom.
Yet another embodiment of the label for the eighth multilayered volume hologram structure of the invention is a label used for making the third embodiment of the eighth multilayered volume hologram structure. The aforesaid label is characterized by comprising a release paper, and a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protective film laminated on said substrate in the described order, and further including between said first adhesive layer and said volume hologram layer a patterned area for varying relative adhesion between said second adhesive layer and said volume hologram layer in a site-dependent manner. This label is pasted on a substrate for a certificate or the like upon a release of said release paper therefrom.
With the eighth multilayered volume hologram layer according to the invention, the volume hologram layer can break down certainly upon an intentional photograph replacement or falsification of an personal information area. It is thus possible to make sure of prevention of falsification. With the label for making the eighth multilayered volume hologram structure, the eighth multilayered volume hologram structure can be easily prepared.